How do you conduct a pump test?
The basic principle of a pumping test is that if we pump water from a well and measure the pumping rate and the drawdown in the well, then substitute these measurements into an appropriate formula and calculate the hydraulic characteristics of the aquifer.
What does a well pumping test give you?
The goal of a pumping test, as in any aquifer test, is to estimate hydraulic properties of an aquifer system. Pumping tests can identify and locate recharge and no-flow boundaries that may limit the lateral extent of aquifers as well.
What is a step drawdown pumping test?
A Step-Drawdown Test is an accelerated pumping test for a single well, designed to estimate the aquifer characteristics and performance of a pumped well under three successively higher pumping rates or steps under controlled flow. The work also includes water level and flow rate measurements.
Can an aquifer run out of water?
Depending on geologic and hydrologic conditions of the aquifer, the impact on the level of the water table can be short-lived or last for decades, and it can fall a small amount or many hundreds of feet. Excessive pumping can lower the water table so much that the wells no longer supply water—they can “go dry.”
How long should a pumping test last?
Continuous active pumping tests are normally undertaken for a minimum 48 hours but can be extended into weeks. During this period, the abstraction flow rate and groundwater level in pumping wells and all monitoring wells are recorded at the following frequency.
What is the difference between slug test and pump test?
Mathematically, the Theis equation is the solution of the groundwater flow equation for a step increase in discharge rate at the pumping well; a slug test is instead an instantaneous pulse at the pumping well.
How many observation wells are required for a comprehensive aquifer test?
one observation well
For the purpose of this document, an aquifer test is defined as a controlled field experiment using a discharging (control) well and at least one observation well. The aquifer test is accomplished by applying a known stress to an aquifer of known or assumed dimensions and observing the water level response over time.
What is aquifer transmissivity?
Transmissivity describes the ability of the aquifer to transmit groundwater throughout its entire saturated thickness (Figure 7). Transmissivity is measured as the rate at which groundwater can flow through an aquifer section of unit width under a unit hydraulic gradient.
How does water get into an aquifer?
An aquifer is a body of porous rock or sediment saturated with groundwater. Groundwater enters an aquifer as precipitation seeps through the soil. It can move through the aquifer and resurface through springs and wells.